//	ID : pallab81
// 	PROG : 10596
// 	LANG : C++
// 	2011-07-10-09.35.39 Sunday
//
// 	"I have not failed, I have just found 10000 ways that won't work.
//


#include <iostream>
#include <algorithm>
#include <vector>
#include <sstream>
#include <fstream>
#include <string>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <functional>
#include <bitset>

#include <cstdio>
#include <cmath>
#include <cstring>
#include <climits>
#include <cstring>

using namespace std;

#define fo(i,ed) for(int i = 0 ; i < ed ; ++i )
#define foit(i, x) for (typeof((x).begin()) i = (x).begin(); i != (x).end(); i++)
#define bip system("pause")
#define Int long long
#define pb push_back
#define SZ(X) (int)(X).size()
#define LN(X) (int)(X).length()
#define mk make_pair
#define f first
#define s second
#define SET( ARRAY , VALUE ) memset( ARRAY, VALUE, sizeof(ARRAY) )

const int inf = 210;
int N,E;
int adj[ inf ][ inf ];
int edges[ inf ] ;
int vis[ inf ];
int node_cover;

inline void read() {
    SET( adj, (int)0 );
    SET( edges, (int)0 ) ;
    fo(i,E) {
        int x,y;
        scanf("%d %d",&x,&y);
        adj[x][y]++;
        adj[y][x]++;
        edges[x]++;
        edges[y]++;
    }
}
inline void make_tour(int now_node) {
    int i;
    ++node_cover;
    vis[ now_node ]=0;
    for(i=0; i<inf; ++i) {
        if( adj[now_node][i] > 0 && vis[i]!=0 ) {
            adj[now_node][i]--;
            adj[i][now_node]--;
            make_tour(i);
        }
    }
}
inline bool is_eular() {
    fo(i,N) {
        if( edges[i]==0 )continue;
        if( (edges[i]&1)!=0 )return false;
    }
    SET( vis, (int)-1);
    node_cover=0;
    make_tour(0);
    return (N==node_cover);
}
inline void proc() {
    if(is_eular()==true) {
        printf("Possible\n");
    } else {
        printf("Not Possible\n");
    }
}

int main() {
    while( scanf("%d %d",&N,&E)==2 ) {
        read();
        proc();
    }
    return 0;
}

